Losing my mind with being a mum

I am not sure if this is in the right category but here we go, my daughter is almost 5 months old and I haven’t been out. I feel like I’m ONLY a mom and that nobody views me as “myself” outside of being a mom, I am one of those people as well. I want to get out, just for one night and be free. I don’t regret becoming a parent but I feel like every so often, I am entitled to do something and enjoy my relationship with my spouse. As a couple, not just parents. Every weekend since she’s been born we’ve attended to in laws for events... my mom works most weekends so it’s hard to even get her to take my daughter while I go out. I planned a month ago for my mom to keep my daughter over night as she knew how much I needed this, she booked off work to do this for me. I planned a whole night with my spouse and was so excited... his mother messaged him to have, a family event on the weekend that we planned this. (Surprise? I think not) she didn’t seem to care, and I tried to express this was the only time we could do this as my mom already booked work off. My SIL stated it shouldn’t be an issue because we can always go out after but I wanted a romantic dinner and to do bowling and come home for 10pm and catch up on desperately needed sleep... so it doesn’t work as we’d leave there place after 6pm and they’re a 45 min drive from home (we have a dog so we’d have to go let him out, get ready and call a cab) which leaves us with no time. She’s so one sided as well, she has a son whose 11 months old and goes out every other weekend and complains she doesn’t get “enough time” to have fun.. meanwhile I haven’t been out once. This family event could’ve been held the following weekend, easily. Nobody sees my point, this is the one weekend I had to do something. I can’t do this any other time as my mom works and only was entitled to two vacation days and she booked them for that weekend. My plans are ruined. I could not go to this event but I wanted the time with my SO to connected again as we’ve fallen off our tracks since having a baby.